There are many different types of mug presses available for sublimation. One type maintains a constant heating temperature. For this type of mug press, you set the press to approximately 400 F. Some items may require a lower temperature depending on coatings, so you will need to check with your vendor to find out their recommendations.
The second setting on this type of press is the dwell time, or the time that the mug is heated in the mug press. The dwell time is something that will also change based on the size of the mug, as well as the coating on the mug. Sublimation mugs can have a soft coating or a hard coating. Soft coatings are generally cheaper and software as the name denotes, and the sublimation process happens quicker due to those properties, so the dwell time in the mug press will be shorter.
The thing to remember is that the easier the sublimation dyes go into the material, the easier it is for them to come out. Soft-coated mugs are generally not dishwasher safe whereas hard-coated mugs typically are. Again, check with your vendor for information on how the mugs will hold up to washing, or even better, test them yourself.
-Kevin Lumberg, Johnson Plastics Plus